Container with diaphragm



June 1956 s. R. SHEERAN CONTAINER WITH DIAPHRAGM Filed Sept. 11, 1952 :Efl

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STAN .E Y RobERT SHEER/m A TTQENEY United States Patent CONTAINER WITHDIAPHRAGM Stanley R. Sheeran, Niagara Falls, N. Y., assignor to E. I. duPont de Nemours and Company, Wilmington, DeL, a corporation of DelawareApplication September 11, 1952, Serial No. 308,990

2 Claims. (Cl. 206-46) This invention relates to new and usefulimprovements in metal containers for storing or shipping liquidsgenerally and specifically for closed containers in which liquids mayform undesirable skins at the surface interface between the liquid andthe air.

Many liquids, such as suspensions, emulsions, mixtures of components ofhigh and lower vapor pressures, solutions and others have a tendencywhen in a closed container, such as a shipping drum to form a skin atthe surface of the liquid where it has an interface with an air or gasspace. It is difficult to avoid such an air or gas pocket especially inshipping drums or containers because these vary slightly in capacity.Also, a gas space permits volume changes due to temperature variationwithout danger of disruption of the container as is likely to happen ifit were filled to 100% capacity.

For example, the shipment of several grades of aqueous emulsions ofpolyvinyl acetate has caused considerable difiiculty because they have apronounced tendency to form skins on the liquid at the interface withthe air pocket. Such skins are formed when water evaporates from theliquid surface since this causes the emulsions to break down. Such skinsare diflicult to redisperse and removing the skin so formed istroublesome. If any small pieces of the skin get into the emulsion theycause trouble in many final applications.

One object of this invention is the provision of means wherebyvolatilization from the liquid phase in a closed container into a gasphase will be prevented. Another object is to provide a diaphragm whichwill float on the liquid surface in a closed container and effectivelyseparate the liquid and gas phases. A further object is the combinationof a floating diaphragm and gasketing of the closure of a container forshipping liquids. Other objects will be apparent from the followingdiscussion of my invention.

Briefly, I may accomplish my objectives by placing an insolubleimpermeable flexible sheet directly over the surface of the liquid inthe can or drum and bring the edges of the sheet up and over the openedge of the container in such a manner that the sheet serves to separatethe liquid from the gas or air space. Then I place the cover on thecontainer using the interposed flexible sheet as a gasketing means. Thesheet must be of suflicient strength relative to the size of containerand weight of contents to withstand the physical strain when thecontainer is rolled on its side or is stood upside down in shipping. Thesheet must be inert to the contents of the container and substantiallyimpenetrable to both the liquid and gas components.

The accompanying drawings illustrate the essential principles of myinvention.

Fig. 1 is a view, part in elevation and part in vertical cross section,of a filled drum with closure at the top.

Fig. 2 is a vertical cross section view of the filled drum of Fig. 1lying on its side.

In the drawings the liquid 2 in container 1 is separated from the airspace 4 by flexible film 3 which latter funcice vapors or liquid intosaid air space. Closure of the container is effected by cover 5 which issecurely fastened to drum rim or lip 7 by a suitable conventionalcircular clamp 6 fitting around the top or lip of the drum. The flexiblefilm 3 extends over the top of the drum and this portion serves as agasket between said top or chime 7 and the edge of the cover 5. Ifdesired, additional gasketing material may be used between the drumcover and the chime, depending upon the requirements of each case.

Figure 2 illustrates an important principle of my invention. Theflexible film 3 adapts itself to separate the liquid phase 2 from thevapor or gas phase 4 even when the filled drum is on its side. Theseparating film can adapt itself to any position of the filled drum,although in general it will be preferable to keep the drum in theupright position.

As a floating diaphragm sheet I envisage the use of rubber, natural orsynthetic, polyethylene, neoprene, polyacrylonitrile, or other syntheticpolymeric materials, cellulosic materials such as cellulose esters,waxed or pachmentized paper, and in fact any material that will form asheet of sufficient strength and flexibility. The material in sheet formmust be impervious to the liquid components concerned and also to thegas or vapors present in the gas phase. Also, the material must be inertto both the liquid and gas.

My invention is suitable for packaging for shipment or for storage inclosed containers any liquid material such as emulsions of polyvinylacetate or other ester derivatives of polyvinyl alcohol. Any liquidwhich may tend to undergo separation of a component whereby a film isformed when packaged in a closed container with an air or gas pocketwill benefit by the use of a flexible diaphragm floating on the liquidsurface and separating the two phases. Also, where a component in theair or gas pocket will react undesirably with a liquid component the useof a diaphragm is indicated, such as in inks, paints, varnishes, etc.

Certain liquids which contain corrosive materials such as petroleumproducts containing hydrogen sulfide will cause corrosion byconcentrating in condensed droplets of liquids such as water on thecontainer walls above the liquid level. In these cases a floatingdiaphragm separating the gas and liquid phases is often very useful inshipping containers.

Specifically, my invention has been found useful for the shipment ofaqueous polyvinyl acetate emulsions. The tendency of such emulsions toform undesirable films at the air-liquid interface has been stopped bythe use of the flexible filrn or diaphragm which separates the liquidand gas phases in the container.

I claim:

1. In a shipping drum having an opening of substantially the samediameter as the side wall of the drum at the section where the cover isapplied, the combination when said drum is in the upright positioncomprising a liquid in said drum, the upper level of said liquid beingin spaced downward relationship to the lip of said drum, a rigidremovable cover secured to the lip of said drum, the inner surface ofsaid cover being in upwardly spaced relationship to the upper surface ofsaid liquid, and a flexible diaphragm impervious to said liquid, saiddiaphragm floating on the upper surface of said liquid and completelycovering said liquid in said drum and having the edge of said diaphragmsecurely fastened between the cover and the lip of said drum, saiddiaphragm substantially completely separating the liquid and the gasphases in said drum.

2. In a shipping drum having an opening of substantially the samediameter as the side wall of the drum at the section where the cover isapplied, the combination when said drum is in the upright positioncomprising a tions as an impervious diaphragm to prevent passage ofpolyvinyl acetate emulsion in said drum, the upper level d laid emulsionbeing :in spaced downward relationship to the lip of said drum, a rigidremovable cover secured to the lip of said drum, the inner surface ofsaid cover being in upwardly spaced relationship to the upper surface ofsaid anulsion, and a flexible diaphragm impervious 5 t0, said-emulsion,said diaphragm floating on the upper Surface of said emulsion andcompletely covering said emulsion-in said drum and having the edge ofsaid diaphragm securely fastened .between the cover and the lip of saiddrum, said diaphragm substantially completely 10 separating the emulsionand the gas phases in said drum.

References Cited in the file of this patent UNITED STATES PATENTS KeaneOct. 12, 1898 Althoff Apr. 16, 1929 Acly May 15, 1934 Graser Dec. 8,1936 Scudder Dec. 22, 1936 Florian Feb. 17, 1942 Shores May 12, 1942 DeKiss June 19, 1945 FOREIGN PATENTS Great Britain 1844

1. IN A SHIPPING DRUM HAVING AN OPENING OF SUBSTANTIALLY THE SAMEDIAMETER AS THE SIDE WALL OF THE DRUM AT THE SECTION WHERE THE COVER ISAPPLIED, THE COMBINATION WHEN SAID DRUM IS IN THE UPRIGHT POSITIONCOMPRISING A LIQUID IN SAID DRUM, THE UPPER LEVEL OF SAID LIQUID BEINGIN SPACED DOWNWARD RELATIONSHIP TO THE LIP OF SAID DRUM, A RIGIDREMOVABLE COVER SECURED TO THE LIP OF SAID DRUM, THE INNER SURFACE OFSAID COVER BEING IN UPWARDLY SPACED RELATIONSHIP TO THE UPPER SURFACE OFSAID LIQUID, AND A FLEXIBLE DIAPHRAGM IMPERVIOUS TO SAID LIQUID, SAIDDIAPHRAGM FLOATING ON THE UPPER SURFACE OF SAID LIQ UID AND COMPLETELYCOVERING SAID LIQUID IN SAID DRUM AND HAVING THE EDGE OF SAID DIAPHRAGMSECURELY FASTENED BETWEEN THE COVER AND THE LIP OF SAID DRUM, SAIDDIAPHRAGM SUBSTANTIALLY COMPLETELY SEPARATING THE LIQUID AND THE GASPHASES IN SAID DRUM.